The human visual system can operate in a wide range of illumination levels, due to several adaptation processes working in concert. For the most part, these adaptation mechanisms are transparent, leaving the observer unaware of his or her absolute adaptation state. At extreme illumination levels, however, some of these mechanisms produce perceivable secondary effects, or epiphenomena. In bright light, these secondary effects include bleaching afterimages and adaptation afterimages, while in dark conditions these include desaturation, loss of acuity, mesopic hue shift, and the Purkinje effect.
Standard displays, such as computer monitors, can reproduce only a fraction of the dynamic range typically encountered in natural environments. Images and videos viewed on conventional displays, therefore, generally do not engage the luminance adaptation mechanisms that the visual system regularly undergoes in real environments. For a display to realistically reproduce the visual experience of high-dynamic-range (HDR) content, it would be desirable to also reproduce the visual experience associated with adapting to a wide dynamic range.
One way to tackle this problem is to design monitors that support larger bit-depths and maximum brightnesses (i.e., luminances), thus placing the burden of performing adaptation on the observer's visual system. However, aside from the complications of turning such prototypes into commercial products, some limitations are inherently unsolvable; e.g., if very bright objects are displayed with proportionally strong radiances on the screen, the viewer may experience discomfort. Moreover, such strategies only address the case of very bright scenes, whereas a display accurately reproducing an extremely low-light scene could only be viewed in total darkness, as any ambient light would prevent the viewer from completely adapting to the display.
Thus, there is a need for addressing these issues and/or other issues associated with the prior art.